There is a continuing demand for petroleumderived fuel products and particularly high octane gasoline and high quality light distillate products. The impending fossil fuel shortage however, has aggravated the demand requirements thereby forcing the refiner to look for other ways of providing the necessary products. In their efforts to optimize gasoline production, for example, refiners have been forced to use increasingly lower quality, heavier, more refractory charge materials resulting in the formation of gasoline boiling range fractions (such as coker naphtha) that are poor in quality (low octane) and high in impurities such as sulfur and/or oxygen.